Patek Philippe Annual Calendar Regulator

In 1991, the soon-to-be graduates at the Geneva School of Engineering were presented with their final project prior to receiving their diploma �?simplify the perpetual calendar.

Although the task was easier said than done, their work led to the inception of the annual calendar complication, patented by Patek Philippe in collaboration with the bright engineering minds at the GSE. Five years later, Patek debuted the Reference 5035 �?the watch that marked the world’s first-ever annual calendar movement and finally bridged the gap between a triple-date function and the formidable quantième perpétuel.

This example, a Reference 5235G-001, features a neat ‘regulator�?display for optimal legibility and is housed in a sleek, 40.5mm 18K white gold case with a sapphire crystal, a signed crown, and a smooth, polished bezel. It features a vertically satin-finished silver dial with a pair of recessed subsidiary registers indicating hour and minutes, as well as day and month apertures flanking the 12 o’clock marker and a central seconds hand.

Powered by Patek Philippe's Calibre 31-260 S self-winding micro-rotor movement, it comes fitted to its signed, black alligator leather strap with a signed, 18K white gold pin buckle and includes all of its factory ephemera �?including its complete inner and outer box set, signed leather folio, books, and a Certificate of Origin dated December, 2018.